In search of vitamin D
The right dose for bone health depends on key factors.
If you're wondering how much vitamin D will keep your bones healthy, you're not alone. Supplements of no more than 400 international units (IU) of vitamin D and 1,000 milligrams (mg) of calcium per day don't do much. A recent study in the New England Journal of Medicine said high-dose vitamin D (800–2,000 IU) reduced hip fractures by 30%. "The exact dosage that's required is still very controversial," says Dr. Jill Paulson, an instructor in medicine at Harvard Medical School.